LIST OF ILLUSTRATIONS xxiii 



FIG. PAGE 



180. Dicyema paradoxum, male 229 



181. Rhopalura giardii, male 230 



182. ,, ,, female 230 



183. Salinella, longitudinal section 231 



184. ,, transverse ,, 231 



185. Planaria, digestive and excretory systems 234 



186. ,, nervous system 234 



187. reproductive system 236 



188. Transverse section of a Planarian 237 



189. Fasciola hepatica 237 



190. ,, ,, section of integument 238 



191. ,, ,, internal organisation 239 



192. ,, terminal part of reproductive apparatus . . 240 



193. ,, development 241 



194. Tseniasolium 242 



195. head 243 



196. ,, transverse section 244 



197. proglottis 245 



198. ,, ,, ripe proglottis 246 



199. development 247 



200. Various Planarians . .251 



201. Gunda segmentata 252 



202. Digenetic Trematodes 253 



203. Gyrodactylus and Polystomum 254 



204. Temnocephala 255 



205. Actinodactylella 256 



206. Tetrarhynchus 257 



207. Taenia echinococcus 257 



208. Ligula 257 



209. Caryophyllseus 258 



210. Gyrocotyle 258 



211. Archigetes ' 258 



212. Section of body -wall of a Triclad 259 



213. Parenchyma of Flat-worm 259- 



214. Diagram of Rhabdoccele 261 



215. Polyclad 261 



216. Triclad 262 



217. Flame-cell 264 



218. Reproductive organs of Mesostomum ehrenbergii . . . .267 



219. Developing egg of Planocera 269 



220. Embryo of Planocera 270 



221. Miiller's larva of Yungia 271 



222. Embryos of Dendrocoelum 272 



223. Embryo of Temnocephala 273 



224. 274 



225. A Cysticercoid 276 



226. with head evaginated 276 



227. Cyst of Tsenia echinococcus . . . 277 



